sde: add optional `-x` support for `set -x` the sde frontend

Signed-off-by: Alejandro Mery <amery@geeks.cl>

bin/sde

@@ -37,6 +37,14 @@ readlink -f /bin/sh 2>&1 > /dev/null
 [ $? -eq 0 ] ||
 	echo_abort 1 '`readlink` doesnt support -f, please update it.'
 
+if [ "x-x" = "x${1:-}" ]; then
+	XTRACE=yes
+	shift
+	set -x
+else
+	XTRACE=
+fi
+
 # find libsde.in
 #
 if [ -z "$SDEROOT" ]; then
@@ -63,7 +71,7 @@ if [ "$( readlink -f "$0" )" != "$SDEROOT/bin/sde" ]; then
 	if [ "$1" = "--loop" ]; then
 		echo_abort 2 'loop detected, abort.'
 	else
-		exec "$SDEROOT/bin/sde" --loop "$@"
+		exec "$SDEROOT/bin/sde" ${XTRACE:+-x }--loop "$@"
 	fi
 elif [ "$1" = "--loop" ]; then
 	shift